
whisk flour and salt in a large bowl. With a pastry blender or 2 forks, cut in butter until it resembles coarse crumbs.
Add sour cream; stir until dough comes together. Shape the dough into disks. On a lightly floured surface, roll out to a 14” round.
Transfer to a 9” deep pie plate. Trim overhang and crimp edges. Chill crust at least 30 Minutes.
Preheat oven to 400 degrees. Line pie shell with parchment paper and fill with pie weights or beans. Bake for 12 Minutes. Remove from oven, take out pie weights and lower heat to 325 degrees.
Prepare filling:
Heat olive oil in a large skillet over medium heat. Add mushrooms and sauté mushrooms until wilted and liquid has evaporated. Place mushrooms into partially baked pie shell.
Combine, eggs, milk, pesto and cheese in a large bowl. Season with salt and pepper. Carefully pour mixture over mushrooms and bake until set, about 30-35 minutes. Let cool a bit before slicing.

